Underground bugged?

Now 3 times in a row after we killed the last boss in phase 3 of a challenge underground with all 5 mods on we get a message 'Recover the report'. The waypoint leads us all the way back to the start of the phase where the elevater is. From there we cant go further back and we can only end the underground session.

Anyone else had this problem of if so is there anything you can do to finish the mission?